Send a big message online and it's chopped into small 'packets,' each stamped with a destination address, sent separately, and reassembled at the end. The internet moves everything as addressed postcards, not one long letter.
Cut it up, ship it, reassemble
The internet does not send your message as one long stream. It chops it into small packets, each stamped with a destination address, and sends them independently. Different packets may take different routes and arrive out of order; the receiver reassembles them. This packet switching is what makes the internet robust — if one path fails, packets simply route around it.
Every device on a network has an IP address — a numeric label like a postal address. Routers read the destination address on each packet and forward it one hop closer, again and again, until it arrives. No single machine knows the whole route.
binary 00001010 = 10
Addresses and data are ultimately binary. Each part of an IPv4 address is one byte — a number from 0 to 255, exactly what 8 bits can hold.
- Draw 5 routers as dots and connect them with a few links (not every pair).
- Pick a source and destination. Send a packet: at each router, forward it along a link that gets closer to the destination.
- Now cut one link on your chosen path. Re-route the packet — can it still arrive?
- Explain why packet switching survives a broken link better than a single fixed line would.
What you should see: You forwarded a packet hop by hop and saw why decentralized routing makes the internet fault-tolerant.